1. Field of the Invention
This invention relates to a method and an apparatus for separating wires, and more particularly to a method and an apparatus suited to a group of wires, such as a telecommunication cable composed of numerous cores, for separating and transferring the group of wires one by one efficiently and automatically.
The wire separating method and apparatus of this invention are useful for example when a group of cores are individually separated and transferred for a continuity test or defective contact test as in the electrical test of telecommunication cables, or when an unknown number of grouped wires are checked for the accurate total number of the wires.
2. Description of the Prior Art
We have already obtained Japanese Pat. No. 578047, published Jan. 26, 1970, on a method and an apparatus for automatically individually separating a group of wires. The method and apparatus will be described below with reference to FIG. 1. The core group 1 of a telecommunication cable, for example, is placed into an inlet 7 and pressed against a rotary disc 3 having for example one notch 2 formed in its peripheral side face to force one core 6 into the notch 2 by a pressing member 4. The core 6 received in the notch 2 is sent forward by the rotation of the rotary disc 3 while being confined in the notch 2 by a holder block 5 provided around the rotary disc 3 and facing the peripheral side face as slightly spaced apart therefrom, and is released from the disc 3 at an outlet 9. Indicated at 5' is a block having a face 52' which, like the face 52 of the holder block 5, is opposed to the periphery of the rotary disc 3. The faces 52 and 52' are positioned close to the periphery of the rotary disc 3 and spaced apart therefrom by such a small distance that will not permit the core 6 to engage in the clearance between the disc periphery and the faces 52, 52'. The holder block 5 and block 5' have wall faces 51 and 51' respectively, defining the core inlet 7.
Since the core group 1 within the inlet 7 is held pressed by the pressing member 4 against the notched peripheral side face of the rotary disc 3 according to this method, the cores 6 can be forced into the notch 2 one at a time and separated and transferred one by one.
This method, however, has the drawback that the pressing member 4, although pressing the core goup 1 in the inlet 7 against the periphery of the rotary disc 3, sometimes fails to engage the core 6 into the notch 2. Such misengagement will take place when the pressure of the pressing member 4 on the core group 1 forms at the lower end of the inlet 7 a compacted arrangement of intimately fitting cores 6, with the resulting friction between the cores restraining the engagement of the core into the notch. Additionally, while the cores of group 1 in the inlet 7 are being separated and transferred one after another, a void 8 is likely to occur within the group 1, forming a bridge of cores in which the cores are arranged concentrically along the pressing surface of the pressing member 4 and along the inner wall faces 51, 51' defining the inlet 7. The pressing member 4 would then be unable to press the cores except those positioned close to the inner walls, giving rise to the tendency of the cores to retain their position against the pressure and enhancing the likelihood of misengagement. The phenomenon of misengagement also occurs when intersecting cores in the group 1 come into contact with the notched portion, since both the cores are unable to fully engage in the notch 2 at the same time.
To overcome these problems, we have proposed an improved wire separating method (Japanese patent application No. 50-15127, filed Feb. 7, 1975), in which a group of wires placed in a core inlet are separated while being subjected to a rocking motion perpendicular to the longitudinal direction of the group of wires, the rocking motion being imparted by an eccentric rotary disc disposed under a rotary disc of the same type as already described formed in its peripheral side face with a notch suitable for accommodating one core. The eccentric rotary disc is mounted at an eccentric portion thereof on the drive shaft of the notched rotary disc and rotated in synchronism therewith in such manner that the eccentric disc is out of contact with the group of cores when the notch of the notched disc is positioned in the inlet but comes into contact with the core group to press the cores at right angles to the longitudinal direction thereof when the notch is away from the inlet. The changes in the position of the periphery of the eccentric disc relative to the group of cores due to its rotation about its eccentric axis give the core group a repeated rocking motion perpendicular to the longitudinal direction thereof, thereby collapsing the compact arrangement, if any, of the cores at the lower end of the inlet or a bridge-like core arrangement to reduce the likelihood of the above-mentioned misengagement.
The improved method, however, is still unable to fully obviate such an objectionable core arrangement. When rocking the group of cores transversely thereof, it is difficult to afford a rocking motion of sufficient amplitude and therefore to ensure a satisfactory effect at all times in collapsing the undesirable arrangement of cores in the inlet. Moreover it is impossible, by the transverse rocking motion alone, to completely eliminate the misengagement of the core in the notch which takes place when an intersection of cores comes into contact with the notched portion as experienced in the case where the cores are stranded. In fact, difficulties are still encountered with the improved method in completely individually separating the cores of telecommunication cables because they are in the form of strands such as pair of quad strands and have many intersections between the cores.
The improved method has another disadvantage that the eccentric disc, which repeatedly gives a rocking motion to the group of cores always at the same position, is likely to cause damage to the insulating covers on cores of telecommunication cables by the repeated impact.